The present invention relates to a method of determining the length of a line, more specifically the length of a telephone line between a subscriber station and an exchange of a telephone system.
In some applications, it is important to know the length of a telephone line between a connected subscriber apparatus and the exchange of a telephone station.
When measuring electric conductors or lines, it is generally known to measure the length of the transmission line by arranging or installing special equipment which is intended solely for measuring the length of the line.
For instance, JP-A-60 138401 teaches the use of special equipment for measuring the absolute length of a transmission line, by providing a phase measuring instrument for signals delivered to the line whose length is to be measured. A measurement of the length of the line can be obtained, by counting the number of times that a test signal passed through the line has exceeded two (2).
Methods are also known which use special bridge circuits and different designs of such bridge circuits for the purpose of measuring the length of a conductor, see for instance SE-B-348 560.
A common feature of these earlier known arrangements and methods thus resides in the necessity of taking more or less complicated measures in carrying out the intended measuring procedure, which can result in expensive and complicated handling procedures.